Department of Cardiology, The First Affiliated Hospital, Jiangxi Medical College, Jiangxi Hypertension Research Institute, Nanchang University, Nanchang, 330006, P. R. China.
State Key Laboratory of Food Science and Resources, School of Food Science and Technology, Nanchang University, Nanchang, 330047, P. R. China.
Mikrochim Acta. 2024 Jun 13;191(7):387. doi: 10.1007/s00604-024-06437-7.
A novel construction strategy is introduced for an ultrasensitive dynamic light scattering (DLS) immunosensor targeting alpha fetoprotein (AFP). This approach relies on a self-assembled heptamer fusion protein (A1-C4bpα), incorporating the dual functions of multivalent recognition and crosslinking aggregation amplification due to the presence of seven AFP-specific A1 nanobodies on the A1-C4bpα heptamer. Leveraging antibody-functionalized magnetic nanoparticles for target AFP capture and DLS signal output, the proposed heptamer-assisted DLS immunosensor offers high sensitivity, strong specificity, and ease of operation. Under the optimized conditions, the designed DLS immunosensor demonstrates excellent linear detection of AFP in the concentration range 0.06 ng mL to 512 ng mL, with a detection limit of 15 pg mL. The selectivity, accuracy, precision, practicability, and reliability of this newly developed method were further validated through an assay of AFP levels in spiked and actual human serum samples. This work introduces a novel approach for constructing ultrasensitive DLS immunosensors, easily extendable to the sensitive determination of other targets via simply replacing the nanobody sequence, holding great promise in various applications, particularly in disease diagnosis.
一种针对甲胎蛋白（AFP）的超灵敏动态光散射（DLS）免疫传感器的新型构建策略被提出。该方法依赖于自组装的七聚体融合蛋白（A1-C4bpα），由于 A1-C4bpα 七聚体上存在七个针对 AFP 的 A1 纳米抗体，因此具有多价识别和交联聚集放大的双重功能。利用抗体功能化的磁性纳米粒子进行靶标 AFP 捕获和 DLS 信号输出，所提出的七聚体辅助 DLS 免疫传感器具有高灵敏度、强特异性和操作简便的特点。在优化条件下，设计的 DLS 免疫传感器在 0.06 ng mL 至 512 ng mL 的浓度范围内对 AFP 表现出优异的线性检测，检测限为 15 pg mL。通过对加标和实际人血清样品中 AFP 水平的测定，进一步验证了该新方法的选择性、准确性、精密度、实用性和可靠性。这项工作提出了一种构建超灵敏 DLS 免疫传感器的新方法，通过简单替换纳米抗体序列，很容易扩展到其他目标的灵敏测定，在各种应用中具有很大的应用前景，特别是在疾病诊断中。
